package org.apache.solr.core;

import org.apache.lucene.codecs.Codec;
import org.apache.lucene.codecs.PostingsFormat;
import org.apache.lucene.codecs.lucene40.Lucene40Codec;
import org.apache.solr.schema.IndexSchema;
import org.apache.solr.schema.SchemaAware;
import org.apache.solr.schema.SchemaField;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Per-field CodecFactory implementation, extends Lucene's and returns postings
 * format implementations according to the schema configuration.
 * 
 * @lucene.experimental
 */
public class SchemaCodecFactory extends CodecFactory implements SchemaAware {
	private Codec codec;

	// TODO: we need to change how solr does this?
	// rather than a string like "Pulsing" you need to be able to pass
	// parameters
	// and everything to a field in the schema, e.g. we should provide factories
	// for
	// the Lucene's core formats (Memory, Pulsing, ...) and such.
	//
	// So I think a FieldType should return PostingsFormat, not a String.
	// how it constructs this from the XML... i don't care.

	@Override
	public void inform(final IndexSchema schema) {
		codec = new Lucene40Codec() {
			@Override
			public PostingsFormat getPostingsFormatForField(String field) {
				final SchemaField fieldOrNull = schema.getFieldOrNull(field);
				if (fieldOrNull == null) {
					throw new IllegalArgumentException("no such field " + field);
				}
				String postingsFormatName = fieldOrNull.getType()
						.getPostingsFormat();
				if (postingsFormatName != null) {
					return PostingsFormat.forName(postingsFormatName);
				}
				return super.getPostingsFormatForField(field);
			}
		};
	}

	@Override
	public Codec getCodec() {
		assert codec != null : "inform must be called first";
		return codec;
	}
}
